A pair of implants that form a digital bridge between the brain and spinal cord have enabled a ‘test pilot’ patient to stand better and walk again, promising an innovation that could one day transform people’s lives suffering from paralysis.
Led by researchers from the Ecole polytechnique fédérale de Lausanne (EPFL), the investigation involved a 40-year-old man named Gert-Jan, who had been paralyzed by a bicycle accident more than a decade ago.
Gert-Jan had previously found some ability to walk with the aid of a front-wheeled walker. For the three years prior to enrolling in the last test, he had reached a “neurological recovery plateau”.
One of the implants tested on Gert-Jan was placed above his brain, decoding the electrical signals that triggered movement. He was communicating with another implant connected to the part of the spinal cord responsible for triggering movement in his legs. Together, they are able to bypass the injured section of his cervical spinal cord, wirelessly restoring the link between his brain and body.
The implants not only seemed to restore some of the damaged connectivity in Gert-Jan’s central nervous system as they were used: after a year of working with the implants and physical treatment, her ability to walk s was improved to the point that he could walk on crutches even when the devices were turned off.
It’s a good sign at least some of his neurons have reorganized to restore communication, the researchers say.
“We have created a wireless interface between the brain and the spinal cord using brain-computer interface (BCI) technology that turns thought into action,” explains Grégoire Courtine, neuroscientist at EPFL.
Over the course of 12 months, the digital bridge implants were shown to help Gert-Jan walk and stand more naturally, without the additional wearable motion sensors used in previously tested technologies to detect and stimulate movement. Additionally, the brain-spine interface (BSI) introduced in this trial meant that he could climb stairs and traverse varying terrain (like steep ramps, for example) – challenges he could not handle before. .
The system key is a series of artificial intelligence algorithms able to adapt and learn with user prompting. The patient must train the model so that it can decode which brain thoughts correspond to which movements, a process that takes a surprisingly short time.
“The patient must first learn to work with their brain signals, and we must also learn to correlate these brain signals with spinal cord stimulation,” said Jocelyne Bloch, EPFL neurosurgeon. “It’s quite short: in a few sessions, everything comes together.”
Although this type of system does not work for all types of spinal cord injuries and has only been tested on one person, there is huge potential here for using technology and AI to bridge the gap. deficiencies in the nervous system caused by injury.
For Gert-Jan, progress has sometimes been slow, but his quality of life has been dramatically improved by the implants he has used at home. For example, he can now stand in a bar enjoying a beer with friends – something seemingly small that most of us take for granted, but which means a lot to Gert-Jan and his recovery.
“This simple pleasure represents a significant change in my life,” he says.
The research has been published in Nature.